Open-air golf carts are often utilized in extreme temperatures. For instance, when golfers play during the hot temperatures of summer or in the cold temperatures of winter, it is desirable to maintain a comfortable environment while driving around a golf course. One approach to address the problem would be to install a portable air conditioner in the golf cart itself. However, air conditioning units are very expensive, bulky, contain elements that are potentially harmful to the environment, and often require an AC external power source to operate. Because most golf carts run on battery power, it would be very difficult to power an air conditioning unit unless it was small enough or could be powered by its own battery.
One other major concern on many golf courses is to avoid transmitting potentially harmful bacteria between humans that may grow in standing water on the courses. Golf courses often use reclamated water in its ponds, streams and to water the grass on the course. Some golf courses have experienced instances of sickness and deaths to patrons who have come into contact with contaminated water on the course. It is certainly desirable to prevent golf course employees or patrons from contaminating the water supply, especially when it comes to water that may sit dormant for many hours in warmer climates.
The present invention addresses these concerns by providing a portable air condition unit that both cools and heats the surrounding air during the usage of a golf cart. The present invention makes use of a portable apparatus that includes a reservoir for cooled liquid or ice that is isolated from human contact by means of a locking mechanism, and may be accessible only by those authorized to do so. The reservoir is insulated with the exception of its bottom surface, which doubles not only as the bottom area of the reservoir, but also as the top to a heat sink that provides the area below the reservoir which acts as an air duct. The heat exchange system is substantially hollow but may also contain a series of fins that are in contact with the reservoir. The heat exchange system is designed to maximize the exposure of the air to the exposed surface area of the reservoir since the only air that is cooled is the air that directly comes in contact with the exposed surface of the reservoir. Generally, the heat exchange system should be located on the bottom of the unit so the heat transfer between the outside air and the bottom surface area of the reservoir may occur even when there are very low levels of cooled liquid in the reservoir. This would take advantage of the principle that the coldest liquid will always remain at the bottom of the container while in a given environment thus making an even more efficient cooling system.
When the reservoir is filled with cold liquid or ice, the exposed surface area of the reservoir becomes cooled to the temperature of the reservoir's contents. The heat exchange system is connected on one side by an air intake chamber and by an air exhaust chamber on the other. Warm air is drawn into the intake chamber from a battery-powered variable-speed motorized fan that creates a vacuum. The fan then pushes the warm air through the heat exchange system and is dehumidified and cooled by coming into direct contact with the exposed surface area of the reservoir and fins that extrude perpendicularly from the bottom surface of the reservoir within the coil system. The fins provide resistance and vary the direction of the air, creating turbulence. Also, coolness from the exposed surface area is transferred down through the fins providing additional cooled surface area, which contacts and further cools the air. The turbulence greatly enhances the thermal conductive capacity of the system so that the heat transfer can occur at a highly efficient rate and maximizes the time that the temperature of the exposed surface of the reservoir remains cold. The cooled air is then propelled into the exhaust chamber where it is thrust into the external environment and may be directed at an individual or used to generally cool a surrounding area.
Over a period of time while cold fluid comes in contact with the surface of the heat exchanger that is exposed to the interior of the reservoir or container, a narrow region next to the surface of the heat exchanger exists where the velocity of the fluid is zero and rapidly changes to a finite number as the distance from the surface increases. This is known as the boundary layer. The fluid's velocity is zero due to a variety of factors ranging from molecular attraction to surface tension to friction. When a boundary layer forms, it may prevent the surface area of the fins from efficient thermal conductivity between the inner reservoir to the surface area of the fins. This lack of conduction is due to the layer of insulation the boundary layer creates from the fluid directly adjacent to the exposed surface of the heat exchanger.
When the ambient air temperature is sufficiently cold, the unit also serves to heat the outside air by drawing in cool air into the unit and passing the air through a series of heated coils before being expelled back into the environment. The unit works much in the same way as a hair dryer heats ambient air. Generally, the user may select either the heating or cooling process by a switch that redirects the air through a given path depending on whether heating or cooling is desired. The air conditioning unit itself may be set to switch on only when one or more persons are seated within the golf cart. This is accomplished by using a seat switch to sense the presence of a person in either the driver or passenger seat of the cart.
The reservoir may also include additional features such as holding area for beer and soda cans to keep them cold and an aroma cartridge to scent the surrounding air. The reservoir may also be removed from the unit so that its contents may be stored in a refrigerated environment. This allows multiple reservoirs to be used in succession thereby increasing the amount of time that cool air may be generated. Another feature of the apparatus is that the airflow may be directed by means of an extendable hose, which is embedded within the exhaust chamber of the unit. The entire external surface of the unit should be heavily insulated in order to prevent unwanted heat from coming into contact with the reservoir's contents.
It is also understood that to a person of reasonable skill in the art that the underlying claimed invention for a portable air conditioner can be utilized in other applications such as automobiles, boats, RVs, trucks, patio furniture, stadium seating or any similar application.